Capture global Kad lookup traffic

Kad is the most popular P2P file sharing system. It is very difficult to capture all the users' lookup traffic because of its full distributed feature. Previous work could only monitors a subset of the lookup traffic. In this paper, we propose a lightweight method to monitor the global lookup traffic by inserting two `nearest neighbor' peers into the peer at the last iteration of Kad lookup path. Since one of the inserted peer is closer than the last peer definitely, the user's search request would be redirected to the trap node. The experiment performed on eMule0.50a shows that this approach could capture most lookup traffic.